Shaken baby syndrome

In 1971, Norman Guthkelch proposed that whiplash injury caused subdural bleeding in infants by tearing the veins in the subdural space. The term whiplash shaken infant syndrome was introduced by John Caffey, a pediatric radiologist, in 1973, describing a set of symptoms found with little or no external evidence of head trauma, including retinal bleeds and intracranial bleeds with subdural or subarachnoid bleeding or both. Development of computed tomography and magnetic resonance imaging techniques in the 1970s and 1980s advanced the ability to diagnose the syndrome. ==Epidemiology==

The incidence of shaken baby syndrome is unknown due to difficulty in diagnosis, which may be caused by lack of centralized reporting system, absent signs of maltreatment, unclear presentation, and acute head trauma being classified under chronic neglect. Incidence is estimated to be 35 out of 100,000 infants, 65% of these infants have significant neurological disabilities, and 5–35% of infants die as a result of sustained injuries. However, these statistics are presumably underestimates of the actual incidence of SBS, because there are children whose injuries may not be perceived as serious enough to be hospitalized, and those who have been hospitalized but diagnosis was missed. On the other hand, there may be significant overdiagosis of SBS, which would make these findings an over-estimate. Small children are at particularly high risk for abuse associated with SBS given the large difference in size between the small child and the caretaker. In the US, deaths due to SBS constitute about 10% of deaths due to child abuse. ==Risk factors==

Common risk factors for shaken baby syndrome include perceived excessive crying, behavioral health problems, domestic violence history, frustration intolerance, lack of childcare experience, young infant age, young maternal age, multiple births, having a male infant, full-time working, postpartum depression, single parent families and economic adversity. Episodes of colic are greatest at 6 to 8 weeks of age, and studies have shown a peak in SBS incidence during this time as parents may perceive these episodes as excessive crying. Caregivers of any gender can cause SBS, but cases of SBS have been reported to be more common amongst younger parents. Studies have shown increased prevalence of SBS among parents 34 years old or younger, especially 24 years old or younger. Although it had been previously speculated that SBS was an isolated event, evidence of prior child abuse is a common finding. In an estimated 33–40% of cases, evidence of prior head injuries, such as old intracranial bleeds, is present. At the community level, risk factors for shaken baby syndrome include social isolation, lack of recreational facilities, lack of external support from family or governmental agencies, unsafe neighborhoods and societal factors such as poverty. ==Mechanism==

Shaken Baby Syndrome, also known as Shaken Impact Syndrome, is a severe form of child abuse. It occurs when parents or caregivers shake a baby. Evidence indicates early crying pattern as the common trigger for SBS, and it results from a failure in what is usually a normal interaction between infants and caregivers. Effects of SBS are thought to be diffuse axonal injury, oxygen deprivation and swelling of the brain, which can raise pressure inside the skull and damage delicate brain tissue, although witnessed shaking events have not led to such injuries. Direct injuries include skull fractures, cortical contusions, diffuse axonal injuries, and hemorrhages. Indirect injuries includes brain edema and herniation. Traumatic shaking occurs when a child is shaken in such a way that its head is flung backwards and forwards. This swift movement resulted in collision of brain to the skull, potentially tearing blood vessels and leading to bleeding around the brain, resulting in the formation of hematoma. As the hematoma enlarges, it can increase pressure within the skull, causing further injury to the brain. Consequences of SBS The consequences of SBS can be severe and long-lasting. They include learning disabilities, physical disabilities, visual impairment or blindness, and hearing impairments. Affected individuals may also experience speech disabilities, cerebral palsy, seizures, and behavior disorders. Cognitive impairments are common, and in the most severe cases, it can result in death. A biomechanical analysis by F. A. Bandak published in 2005 reported that "forceful shaking can severely injure or kill an infant, this is because the cervical spine would be severely injured and not because subdural hematomas would be caused by high head rotational accelerations ... an infant head subjected to the levels of rotational velocity and acceleration called for in the SBS literature, would experience forces on the infant neck far exceeding the limits for structural failure of the cervical spine. Furthermore, shaking cervical spine injury can occur at much lower levels of head velocity and acceleration than those reported for SBS." Other authors were critical of the mathematical analysis by Bandak, citing concerns about the calculations the author used concluding "In light of the numerical errors in Bandak's neck force estimations, we question the resolute tenor of Bandak's conclusions that neck injuries would occur in all shaking events." Other authors critical of the model proposed by Bandak concluding "the mechanical analogue proposed in the paper may not be entirely appropriate when used to model the motion of the head and neck of infants when a baby is shaken." Bandak responded to the criticism in a letter to the editor published in Forensic Science International in February 2006. ==Diagnosis==

Diagnosis can be difficult as symptoms may be nonspecific. As a result, about 31% of true SBS cases may go unnoticed initially. However, imaging can provide valuable information about a potential SBS diagnosis. Imaging must be performed within at least 24 hours of the suspected injury to detect brain edema characteristic of SBS. A CT scan of the head is typically recommended if a concern is present. they are often incorrectly referred to as a "triad" for legal proceedings; distilled down to retinal hemorrhages, subdural hematomas, and encephalopathy. A 2023 review concluded "research has shown the triad is not sufficient to infer shaking or abuse and the shaking hypothesis does not meet the standards of evidence based medicine". and caregivers may lie or be unaware of the mechanism of injury. Commonly, there are no externally visible signs of the condition. Magnetic resonance imaging may also depict retinal hemorrhaging but is much less sensitive than an eye exam. Conditions that are often excluded by clinicians include hydrocephalus, sudden infant death syndrome (SIDS), seizure disorders, and infectious or congenital diseases like meningitis and metabolic disorders. CT scanning and magnetic resonance imaging are used to diagnose the condition. Classification The US Centers for Disease Control and Prevention identifies SBS as "an injury to the skull or intracranial contents of an infant or young child ( Gestational problems affecting both mother and fetus, the birthing process, prematurity and nutritional deficits can accelerate skeletal and hemorrhagic pathologies that can also mimic SBS, even before birth. ==Prevention==

Interventions by pediatric practitioners and prenatal providers are recommended by the American Academy of Pediatrics. Educating expecting parents about how to soothe an inconsolable child, as well as the dangers of physical impact to an infant, may reduce rates of SBS. Educating babysitters, nannies, and other caretakers about SBS and encouraging them to reach out for help with an inconsolable infant may also reduce its rates. ==Treatment==

Treatment involves monitoring intracranial pressure (the pressure within the skull). Treatment occasionally requires surgery, such as to place a cerebral shunt to drain fluid from the cerebral ventricles, and, if an intracranial hematoma is present, to drain the blood collection. ==Prognosis==

Prognosis depends on severity and can range from total recovery to severe disability to death when the injury is severe. The most frequent neurological impairments experienced by 70% of SBS survivors are learning disabilities, seizure disorders, speech disabilities, hydrocephalus, cerebral palsy, and visual disorders. Endocrine dysfunction is not uncommon. It is recommended that survivors of SBS be referred to medical homes for continuous follow-up by pediatricians and their healthcare team. ==Disputed validity and legal issues==

The association of diagnosed SBS with deliberate assault is a matter of legal and medical contention, with conflicting opinions as to whether one necessarily implies the other. One of the main contentions is that many medical definitions create a biased picture of the defendants, marking them as the aggressor and implicitly providing a guilty verdict. Simply, this diagnosis blurs the line between diagnosis and verdict. According to Gabaeff (2018), shaken baby syndrome is an "unproven hypothesis". Scientific challenges to its validity have been increasing. The concern when combining these two factors is that it allows physicians to provide a definite cause for a condition which can have life-changing legal implications for the person accused of causing it. This is problematic since in many states, such legal sentencing is typically rendered by multidisciplinary child-abuse-prevention teams (physicians, social workers, and law enforcement). Similarly, the Maguire model, suggested in 2011 as a potential statistical model for determining the probability that a child's trauma was caused by abuse, has been questioned. A proposed clinical prediction rule with high sensitivity and low specificity, to rule out abusive head trauma, has been published. In July 2005, the Court of Appeal of England and Wales heard four appeals of SBS convictions: one case was dropped, the sentence was reduced for one, and two convictions were upheld. The court found that the classic triad of retinal bleeding, subdural hematoma, and acute encephalopathy are not 100% diagnostic of SBS and that clinical history is also important. In the Court's ruling, they upheld the clinical concept of SBS but dismissed one case and reduced another from murder to manslaughter. The court did not believe the "unified hypothesis", proposed by British physician J. F. Geddes and colleagues, as an alternative mechanism for the subdural and retinal bleeding found in suspected cases of SBS. In 2012, Norman Guthkelch, the neurosurgeon often credited with "discovering" the diagnosis of SBS, published an article "after 40 years of consideration", which is harshly critical of shaken baby prosecutions based solely on the triad of injuries. Again, in 2012, Guthkelch stated in an interview, "I think we need to go back to the drawing board and make a more thorough assessment of these fatal cases, and I am going to bet ... that we are going to find in every – or at least the large majority of cases, the child had another severe illness of some sort which was missed until too late." Furthermore, in 2015, Guthkelch went so far as to say, "I was against defining this thing as a syndrome in the first instance. To go on and say every time you see it, it's a crime ... It became an easy way to go into jail." Teri Covington, who runs the National Center for Child Death Review Policy and Practice, worries that such caution has led to a growing number of cases of child abuse in which the abuser is not punished. Squier denied the allegations and appealed the decision. As her case was heard by the High Court of England and Wales in October 2016, an open letter to the British Medical Journal questioning the decision to strike off Squier, was signed by 350 doctors, scientists, and attorneys. On 3 November 2016, the court published a judgment which concluded that "the determination of the MPT is in many significant respects flawed". The judge found that she had committed serious professional misconduct but was not dishonest. She was reinstated to the medical register but prohibited from giving expert evidence in court for the next three years. In 2022, Channel 4 in the UK broadcast a documentary called The Killer Nanny: Did She Do It? concerning the Louise Woodward case. In it, civil rights lawyer Clive Stafford Smith stated, "shaken baby syndrome is bullshit". In 2023, a New Jersey appellate court upheld a lower court's decision to bar the inclusion of SBS in two recent child abuse cases. In the decision, several reasons cited. First, there was a split in the pediatrics and biomechanics community over whether shaking alone is sufficient to cause the syndrome. This resulted in expert testimony being dismissed. Additionally, in each case, SBS was difficult to conclude and there was difficulty proving assault otherwise. However, these cases only set precedent for a narrow subsection of cases of SBS where there is no sign of impact to the babies head as well as no other means to demonstrate abuse. Additionally, other conditions can still be reliably diagnosed without confirmation of the original insult, such as asbestos and sports-related injuries. However, the Texas Supreme Court granted a stay of execution to allow his testimony before the Texas House Committee on Criminal Jurisprudence. ==See also==